Large-scale battery energy storage system on Nantucket will provide back-up power and additional supply
National Grid, a leader in developing innovative energy solutions to meet customer and community needs, will install a 48 megawatt-hour battery energy storage system, or BESS, on the island of Nantucket, 30 miles off the Massachusetts coast, to help address some unique energy challenges.
Nantucket has been experiencing significant growth and demand for electricity, both of which are expected to continue for the foreseeable future. The island’s electricity is supplied via two submarine cables that connect with the mainland transmission system on Cape Cod. In the event of a failure on one of the cables, two six-megawatt diesel generators are available to provide partial back-up power. The diesel generators are reaching the end of their useful life and need to be replaced. Additionally, given the growth forecast, the island’s emergency electricity back-up system needs to be expanded, and a third submarine cable likely will be needed in about 12 years.
National Grid explored several options to address these infrastructure needs and the ever-increasing on-island demand for electricity, and came up with a unique solution: the BESS and a new diesel generator that together can supply the island in the event of a cable failure. National Grid expects that with the BESS, the need for a third cable can be delayed for 15 to 20 years beyond the current 12-year forecast. The BESS will be six megawatts with an eight-hour duration, which is also described as a 48 megawatt-hour system, and is being provided by Tesla.
“The BESS provides a very efficient and effective solution to two major energy challenges facing the island,” said Rudy Wynter, president and COO of National Grid’s FERC-regulated Businesses. “Our customers, communities, and policymakers look to us to deliver innovative solutions like this to help advance our clean energy future.”
“The Town of Nantucket commends National Grid’s decision to deploy an innovative energy storage solution on the island,” said Town of Nantucket Energy Coordinator Lauren Sinatra. “We are confident that the proposed project, combined with targeted energy-saving programs and other planned electric infrastructure upgrades, will play a transformational role in meeting Nantucket’s near- and long-term energy needs.”
The BESS is the latest of several National Grid battery systems that are up and running or being planned. The company also has roughly 30 energy innovation pilots underway across the three states it serves, including microgrids, smart grids, community solar projects, geothermal heating and cooling, and distributed energy installations that unlock value for National Grid’s customers and communities, accelerating progress toward a sustainable future.